Work piece carrier head for plating and polishing

Abstract

A work piece carrier head can carry a semiconductor wafer during both plating and polishing operations. The carrier head includes a first component secured to a shaft by which the carrier head can be rotated, translated, and moved up and down, a second component connected to the first component and movable by fluid pressure relative to the first component between retracted and extended positions, and a third component connected to the first and second components for up and down movement between wafer loading or unloading and wafer plating or polishing positions. The third carrier head component includes a contact element by which electrical contact with the wafer is provided to permit wafer plating.

What is claimed is:  
     
       1. A work piece carrier head which can carry a semiconductor wafer while conductive material is deposited on the wafer and while conductive material on the wafer is polished comprising: 
       a first carrier head component secured to a shaft by which the carrier head can be rotated, translated, and moved up and down;  
       a second carrier head component connected to said first carrier head component and movable relative to the first carrier head component between a retracted position and an extended position; and  
       a third carrier head component connected to the first and second carrier head components for movement away from said second carrier head component into a wafer loading position, in which the wafer can be loaded onto the third carrier head component, and towards said second carrier head component into a wafer processing position for deposition and polishing of said conductive material, in which the wafer is clamped between the second and third carrier head components, wherein said third carrier head component can support the wafer during said movement and includes a contact element by which power can be carried to the wafer during processing.  
     
     
       2. A work piece carrier head as defined in  claim 1 , wherein said third carrier head component is biased away from said wafer loading position and towards said wafer processing position. 
     
     
       3. A work piece carrier head as defined in  claim 1 , wherein said first and second carrier head components define an expandable volume therebetween, and wherein fluid can be supplied to or discharged from the expandable volume to produce relative movement of the first and second carrier head components. 
     
     
       4. A work piece carrier head as defined in  claim 3 , wherein said relative movement is used to control a distance between a surface of the wafer and a source of plating material during a wafer processing operation. 
     
     
       5. A work piece carrier head as defined in  claim 4 , wherein the distance is in the range of about 0.01-2.0 mm. 
     
     
       6. A work piece carrier head as defined in  claim 1 , and further comprising stops defined on the first carrier head component which limit movement of the second carrier head component and define respective fully retracted and fully extended positions of the second carrier head component. 
     
     
       7. A work piece carrier head as defined in  claim 6 , and further comprising a gimbal mechanism which is rendered .effective when the second carrier head component is released from the stops to assure uniform pressure across the wafer. 
     
     
       8. A work piece carrier head as defined in  claim 1 , wherein the contact element is formed by a contact ring. 
     
     
       9. A work piece carrier head as defined in  claim 1 , wherein the contact element is formed by several conductive pieces which form a contact ring. 
     
     
       10. A work piece carrier head as defined in  claim 1 , wherein the contact element is sandwiched between sections of said third carrier head component, and further comprising a seal mounted between the contact element and one of said sections in order to isolate the contact element from electrolyte. 
     
     
       11. A work piece carrier head as defined in  claim 1 , wherein the second carrier head component includes holes extending through a face thereof by which the wafer can be pulled under vacuum towards and blown under pressure away from the face. 
     
     
       12. A work piece carrier head as defined in  claim 11 , and further comprising a soft backing pad mounted on the face of the second carrier head component and having a rough surface facing the wafer during wafer processing. 
     
     
       13. A work piece carrier head as defined in  claim 12 , wherein said rough surface has feature sizes of 1-20 mils when it is not flattened by the wafer. 
     
     
       14. A work piece carrier head as defined in  claim 3 , wherein said relative movement is used to control pressure at an interface between a surface of the wafer and a polishing pad surface during a wafer processing operation. 
     
     
       15. A work piece carrier head as defined in  claim 14 , wherein the pressure is in the range of about 0-5 psi. 
     
     
       16. A work piece carrier head secured to a shaft that can be rotated, translated, and moved up and down, and which can carry a semiconductor workpiece when suction is applied so that deposition of conductive material on the workpiece and polishing of conductive material on the workpiece can occur, comprising: 
       means for holding the workpiece in a processing position for deposition and polishing of said conductive material, the means for holding including a substantially flat surface with vacuum holes disposed thereon, such that with the workpiece in the processing position and suction applied to the vacuum holes, the workpiece is held to the substantially flat surface;  
       means for moving the workpiece from a loading position to the processing position, the means for moving attached to the means for holding and including a workpiece carrier portion that supports the workpiece and allows for up and down movement of the workpicce on the workpiece carrier portion between the loading position and the processing position; and  
       a contact pin for establishing a conductive path with the workpiece that is disposed within the workpiece carrier portion.  
     
     
       17. A work piece carrier head according to  claim 16  wherein the means for holding further includes a gimbal mechanism. 
     
     
       18. A workpiece carrier head according to  claim 16  wherein the workpiece carrier portion is formed by a clamp ring that is moved between the loading position and the processing position using a plurality of pushrods. 
     
     
       19. A work piece carrier head as defined in  claim 1 , wherein said contact element provides electrical contact with the wafer on a back surface of the wafer. 
     
     
       20. A work piece carrier head as defined in  claim 1 , wherein said contact element provides electrical contact with the wafer on a back surface of the wafer.